optical square
Surveying
noun
An instrument used to establish lines of sight at right angles to each other by using light bent through a right angle by mirrors or a prism.
Origin
Mid 19th century; earliest use found in William T. Brande (1788–1866), chemist.
- be/get liquored up
- begetter
- beggar
- beggar belief (or description)
- beggarliness
- beggarly
- beggarman
- beggar-my-neighbour
- beggars can't be choosers
- beggar's purse
- beggarticks
- beggarwoman
- beggary
- begging bowl
- begging letter
- begin
- Begin, Menachem
- beginner
- beginner's luck
- beginning
- begird
- begob
- beg off
- begone
- be gone on